Why "drags" is used in here? What does it mean?
Native speaker’s answer
To "drag" in this context means to pull something with force. So "drag" is used here in the phrasal verb "drag down" to mean that the low grade she received on her report card is going to affect her overall average grade in the class by bringing it down or making it lower. This is not the most common usage of the word "drag", as it is usually used to describe something being physically pulled.